Method for inducing functional rice to enrich GABA (gamma-aminobutyric acid) and product

Abstract

The invention discloses a method for inducing functional rice to enrich GABA (gamma-aminobutyric acid) and a product, and belongs to the technical field of food processing.The method comprises the steps that brown rice germinates through physical damage in cooperation with chemical stress and then is soaked in water for accelerating germination, and enrichment of GABA in the functional rice is completed. The GABA functional rice prepared by the preparation method disclosed by the invention is high in GABA content, complete in rice grain form and good in product stability, the cooked rice is moderate in hardness, and the palatability and the functionality are improved. In addition, the rice germination time can be remarkably shortened, and the factory production efficiency is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of food processing, and particularly relates to a method for inducing functional rice to enrich GABA and a product. BACKGROUND

[0002] Gamma-aminobutyric acid (GABA) is a non-protein amino acid widely existing in organisms, and has significant physiological regulation functions, such as lowering blood pressure, improving sleep, anti-anxiety and nerve protection. With the rapid development of the functional food market, developing staple food products with high GABA content has become an important direction of the health industry, and the GABA enrichment technology of rice, as the staple food of half of the world's population, has great application potential. With the prevalence of green, nutritious and healthy consumption concepts, more and more people have higher consumption demand for nutritious rice and functional rice, which creates more opportunities for the development of functional rice industry such as GABA rice and opens up a broader market prospect. At present, the mainstream methods for enriching GABA in rice include germination, soaking, microbial fermentation and exogenous addition. Among them, although the treatment methods such as germination and soaking can significantly improve the nutritional value and functional characteristics of brown rice, they cannot fundamentally solve the problems of long cooking time and poor taste of brown rice, and the germination and fermentation are easily affected by the environment, the retention efficiency of rice morphology is low, and the cycle is long, which is difficult to adapt to the large-scale production line.

[0003] Based on the above production status of GABA rice, how to provide a GABA rice preparation technology which takes into account the efficiency, stability and product eating properties, and realizes the efficient enrichment of GABA by activating the endogenous metabolic pathway under the premise of retaining the morphology of rice particles, while meeting the feasibility requirements of industrial production, is a technical problem that needs to be solved by those skilled in the art. SUMMARY

[0004] To solve the above technical problems, the application provides a method for inducing functional rice to enrich GABA and a product.

[0005] To achieve the above purpose, the application provides the following technical solutions.

[0006] A method for inducing functional rice to enrich GABA, wherein brown rice is germinated after physical damage and chemical stress, and then subjected to water soaking and germination treatment to complete the enrichment of GABA in functional rice.

[0007] Beneficial effects: The application damages the brown rice pericarp to a certain extent through precise damage treatment, and the damage processing appropriately retains the rice aleuron layer, which can maximize the retention of nutrients in rice; appropriate damage treatment in combination with germination conditions is beneficial to the enrichment of GABA during the germination process due to stress.

[0008] Preferably, the brown rice is obtained by storing paddy at 0-10℃ for 12-48h, hulling and removing impurities.

[0009] Beneficial effects: Storing paddy at 0-10℃ for 12-48h can keep the paddy in a relatively stable and suitable physiological state, which is helpful for the stability of brown rice quality in subsequent processing. At the same time, this temperature range and time interval can effectively inhibit the growth of microorganisms and abnormal changes in enzyme activity in the paddy, ensuring the quality and safety of brown rice and providing high-quality raw material basis for subsequent GABA enrichment.

[0010] More preferably, the water content of the brown rice is 14%.

[0011] Beneficial effects: This water content will not cause the brown rice to be easily broken and increase the breakage rate in subsequent processing, affecting the physical damage treatment effect. High water content will reduce the toughness of brown rice, increase the broken rice rate during processing, and a large amount of bran powder will be adsorbed on the surface of the rice, increasing energy consumption and reducing efficiency.

[0012] Preferably, the physical damage is two sand and two iron rice mill processing, wherein the current of the first sand roller rice mill is 20-65A, the current of the second sand roller rice mill is 20-30A, the current of the third iron roller rice mill is 40-60A, and the current of the fourth iron roller rice mill is 40-55A.

[0013] Beneficial effects: Using two sand and two iron rice mill and accurately controlling the current parameters of each rice mill can accurately control the damage degree of the brown rice skin. The force of sand roller and iron roller on brown rice is different under different currents. By reasonably combining and adjusting the current, the nutrition of the rice can be maximized while effectively damaging the brown rice skin to promote subsequent germination and GABA enrichment, improving the nutritional value and overall quality of functional rice.

[0014] Preferably, the chemical stress is soaking the rice in a water solution of glutamic acid and calcium chloride for stress germination.

[0015] Beneficial effects: Glutamic acid is a precursor of GABA synthesis, which can provide sufficient raw materials for GABA production. Calcium chloride can regulate the concentration of calcium ions in rice cells, affect signal transduction and enzyme activity in cells, and synergistically enhance the stress effect with glutamic acid, effectively promoting the enrichment of GABA during rice germination.

[0016] Preferably, the soaking time is 2-8h, and the liquid-to-material ratio (mass ratio) is 10-50.

[0017] Beneficial effect: under the above conditions, the rice can fully absorb the effective components in the glutamic acid and calcium chloride aqueous solution, and good conditions are provided for the subsequent GABA enrichment in the germination process. If the soaking time is too short, the rice cannot be fully absorbed, and the stress effect is not good. If the soaking time is too long, the rice may be excessively watered, affecting the germination quality and the GABA enrichment efficiency.

[0018] Preferably, the mass concentration of glutamic acid in the glutamic acid and calcium chloride aqueous solution is 0.1-0.5%, and the concentration of calcium chloride is 10-15 mmol / L.

[0019] Beneficial effect: in this concentration range, glutamic acid can provide an appropriate and sufficient precursor for the synthesis of GABA, and the concentration of calcium chloride can effectively regulate the physiological environment in the rice cells, promote the activity of related enzymes and signal transduction, and the synergistic effect of the two can maximize the induction of GABA enrichment in the rice during the germination process. If the concentration is too low, the stress effect is not obvious, and the GABA enrichment amount is limited. If the concentration is too high, it may be toxic to the rice cells, inhibiting germination and GABA synthesis.

[0020] Preferably, the soaking and germination treatment time is 12-48h, the temperature is 0-35℃, and the humidity is 60-90%.

[0021] Preferably, the soaking and germination treatment further comprises a drying step, and the drying temperature is 40-100℃, and the time is 1-5h.

[0022] A GABA-enriched functional rice prepared by the method for inducing GABA enrichment in functional rice.

[0023] Beneficial effect: the functional rice provided by the present application is beneficial to the immersion of water during cooking, reduces the cooking time of the rice, and improves the cooking indicators such as the rice yield and volume expansion rate, and produces GABA functional rice with high nutritional value, good taste quality and excellent functional characteristics.

[0024] Compared with the prior art, the present application has the following advantages and technical effects:

[0025] The processing method of the functional rice provided by the present application is green, safe, and pollution-free, and can realize large-scale industrial application. The GABA functional rice prepared by the present application has high GABA content, complete rice grain morphology, good product stability, soft and hard cooked rice, improved palatability and functionality. Moreover, the present application can significantly shorten the rice germination time and improve the production efficiency of the factory. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0027] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with specific embodiments.

[0028] The embodiment of the present application provides a method for inducing GABA-enriched functional rice. After the brown rice is germinated by physical damage and chemical stress, the water soaking and germination treatment is given to complete the enrichment of GABA in the functional rice.

[0029] In a preferred embodiment, the brown rice is obtained by hulling and removing impurities after the paddy is stored at 0-10℃ for 12-48h.

[0030] In a more preferred embodiment, the brown rice is obtained by hulling and removing impurities after the paddy is stored at 5℃ for 12h.

[0031] In a more preferred embodiment, the water content of the brown rice is 14%.

[0032] In a preferred embodiment, the physical damage is a two-sand-two-iron rice mill treatment, wherein the current of the first sand roller rice mill is 20-65A, the current of the second sand roller rice mill is 20-30A, the current of the third iron roller rice mill is 40-60A, and the current of the fourth iron roller rice mill is 40-55A.

[0033] In a more preferred embodiment, the current of the first sand roller rice mill is 30A, the current of the second sand roller rice mill is 20A, the current of the third iron roller rice mill is 40A, and the current of the fourth iron roller rice mill is 45A.

[0034] In a preferred embodiment, the chemical stress is to immerse the rice in a water solution of glutamic acid and calcium chloride for stress germination.

[0035] In a preferred embodiment, the soaking time is 2-8h, and the liquid-to-material ratio (mass ratio) is 10-50.

[0036] In a more preferred embodiment, the soaking time is 4h or 6h, and the liquid-to-material ratio is 22 or 25.

[0037] In a preferred embodiment, the mass concentration of glutamic acid in the aqueous solution of glutamic acid and calcium chloride is 0.1-0.5%, more preferably 0.2% or 0.25%, and the concentration of calcium chloride is 10-15 mmol / L, more preferably 10 mmol / L or 12 mmol / L.

[0038] In a preferred embodiment, the soaking and germination treatment is performed for 12-48 h, more preferably 24 h or 36 h, at a temperature of 0-35℃, more preferably 28℃ or 30℃, and a humidity of 60-90%, more preferably 75% or 80%.

[0039] In a preferred embodiment, the soaking and germination treatment is further followed by a drying step, and the drying is performed at a temperature of 40-100℃, more preferably 45℃ or 60℃, for 1-5 h, more preferably 2 h or 3 h.

[0040] The present application also provides a method for inducing GABA-enriched functional rice.

[0041] Unless otherwise specified, the raw materials in the embodiments of the present application are purchased through the market channel.

[0042] In the embodiments of the present application, the rice variety is Luhuaxiang No. 2.

[0043] Unless otherwise specified, the room temperature or normal temperature in the embodiments of the present application refers to 25±3℃.

[0044] In the embodiments of the present application, the solid-liquid ratio or liquid-solid ratio refers to the mass ratio.

[0045] Embodiment 1

[0046] A method for inducing GABA-enriched functional rice by physical damage and chemical stress, comprising the following steps:

[0047] (1) storing the paddy at 5℃ for 12 h, removing impurities after hulling to prepare brown rice;

[0048] (2) drying the brown rice to a moisture content of 14% and then performing physical damage treatment, wherein the current of the first sand roller rice mill is 30 A, the current of the second sand roller rice mill is 20 A, the current of the third iron roller rice mill is 40 A, and the current of the fourth iron roller rice mill is 45 A, to obtain the damaged rice;

[0049] (3) soaking the damaged rice in the aqueous solution for 4 h for chemical stress germination, wherein the liquid-solid ratio is 25, and the aqueous solution comprises glutamic acid with a mass concentration of 0.2% and calcium chloride with a concentration of 10 mmol / L;

[0050] (4) The soaked rice is placed in an incubator for germination treatment, with a germination time of 24 h, a temperature of 30°C, and a humidity of 80%. After the germination treatment, the rice is dried in an oven at 60°C for 2 h to obtain the GABA-enriched functional rice.

[0051] Technical effects:

[0052] The GABA content and taste value of the milled rice, the brown rice obtained in step (1), the ungerminated GABA rice obtained in step (3), and the germinated GABA rice obtained in step (4) are detected.

[0053] The GABA content is determined by colorimetry, and the specific method is as follows:

[0054] 2 g of the sample is ground and placed in a 50 mL centrifuge tube, and 10 mL of deionized water is added. The sample is shaken and extracted for 2 h (30°C, 150 r / min), then centrifuged at 4000 r / min for 5 min, filtered through a 0.22 μm needle filter into a 50 mL volumetric flask, and diluted to volume with distilled water. 1.0 mL of the filtered solution is taken, 0.4 mL of 0.2 mol / L borate buffer (pH = 9.0, boric acid 6.19 g, sodium hydroxide 4 g, added to 500 mL of deionized water, and the pH is adjusted to 9.0), 2 mL of 6% phenol, and 0.8 mL of NaClO with an available chlorine of 10% are added. After vigorous shaking, it is placed in boiling water for 10 min, then in an ice bath for 5 min, and continuously shaken until blue appears. Finally, 4 mL of 60% ethanol is added to the mixture, and the sample is analyzed by ultraviolet-visible spectrophotometry at a wavelength of 645 nm. Six 10 mL centrifuge tubes are prepared, each containing 1.0 mL of standard solution with a concentration of 0.00, 0.04, 0.08, 0.12, 0.16, and 0.20 mg / mL (GABA content of 1 mg / mL), and the absorbance is determined according to the above method. The regression equation is established with the GABA content as the abscissa (x) and the absorbance as the ordinate (y), and the standard curve (y = 1.2329-0.0036, R2 = 0.9957) is drawn. The GABA content is calculated.

[0055] The taste value is determined according to the following method:

[0056] 30 g of the sample is weighed into a stainless steel pot, the ratio of sample to water is kept at 1:1.3, and after mixing, it is placed in an electric rice cooker for 30 min, and then cooled for 2 h. Subsequently, 7 g of rice is weighed at room temperature and the taste value of the rice is analyzed using a taste meter.

[0057] Optimal cooking time: 5 g of sample was placed in a 250 mL beaker, 100 mL of boiling water was added, and then water bath cooking was performed. After 10 min of cooking, 10 grains of rice were randomly taken every 1 min, and a flat plate was used to press on a black background until there was no white core, which was the optimal cooking time;

[0058] The fine rice, the brown rice obtained in step (1), the ungerminated GABA rice obtained in step (3), and the germinated GABA rice obtained in step (4) were cooked according to their respective optimal cooking times, and then cooled to room temperature after 10 min of steaming. Three cooled rice grains were placed on the texture analyzer test platform in parallel, and the texture properties of different rice were determined. Each sample was tested 8 times. The determination conditions were as follows: P / 25R probe was used, the pre-test speed was 1.0 mm / s, the test speed was 0.5 mm / s, the post-test speed was 1.0 mm / s, the compression ratio was 80%, and the trigger force was 5.0 g.

[0059] The fine rice variety was Danhuaxiang No. 2.

[0060] Table 1

[0061]

[0062] Example 2

[0063] A method for inducing GABA-enriched functional rice by physical damage and chemical stress, comprising the following steps:

[0064] (1) The paddy was stored at 5℃ for 12 h, and then dehusked and impurities were removed to prepare brown rice;

[0065] (2) The brown rice was dried to a moisture content of 14% and then subjected to physical damage treatment. The current of the first sand roller rice mill was 30 A, the current of the second sand roller rice mill was 20 A, the current of the third iron roller rice mill was 40 A, and the current of the fourth iron roller rice mill was 45 A, to obtain damaged rice;

[0066] (3) The damaged rice was soaked in an aqueous solution for 6 h for germination by chemical stress, and the liquid-to-material ratio was 22. The aqueous solution contained 0.25% glutamic acid and 12 mmol / L calcium chloride;

[0067] (4) The soaked rice was subjected to germination treatment in an incubator for 36 h at a temperature of 28℃ and a humidity of 75%. After the germination treatment, the rice was dried in an oven at 45℃ for 3 h, to obtain GABA-enriched functional rice.

[0068] Technical effects:

[0069] The GABA content and the taste value of the milled rice, the brown rice obtained in step (1), the ungerminated GABA rice and the germinated GABA rice were detected by the same method as in Example 1, and the detection results are shown in Table 2:

[0070] Table 2

[0071]

[0072] Comparative Example 1

[0073] The difference from Example 1 is only that the physical damage treatment of step (2) includes only one pass of sand roller rice mill treatment and two passes of iron roller rice mill treatment. Specifically, the following steps are included:

[0074] (1) The paddy is stored at 5℃ for 12h, and after hulling and removing impurities, brown rice is prepared;

[0075] (2) The brown rice is dried to a moisture content of 14% and then subjected to physical damage treatment, one pass of sand roller rice mill treatment at 30A and two passes of iron roller rice mill treatment at 40A to obtain damaged rice;

[0076] (3) The damaged rice is soaked in an aqueous solution for 4h for chemical stress germination, with a liquid-to-material ratio of 25, wherein the aqueous solution includes 0.2% glutamic acid and 10mmol / L calcium chloride;

[0077] (4) The soaked rice is placed in an incubator for germination treatment, with a germination time of 24h, a temperature of 30℃ and a humidity of 80%. After the germination treatment, the rice is dried in an oven at 60℃ for 2h to obtain GABA-enriched functional rice.

[0078] Technical effects:

[0079] The GABA content and the taste value of the milled rice, the brown rice obtained in step (1), the ungerminated GABA rice and the germinated GABA rice were detected by the same method as in Example 1, and the detection results are shown in Table 3:

[0080] Table 3

[0081]

[0082] Comparative Example 2

[0083] The difference from Example 1 is only that the physical damage treatment of step (2) is not included. Specifically, the following steps are included:

[0084] (1) The paddy is stored at 5℃ for 12h, and after hulling and removing impurities, brown rice is prepared;

[0085] (2) The brown rice is dried to a moisture content of 14% and then soaked in an aqueous solution for chemical stress germination for 4 h, with a liquid-to-material ratio of 25, wherein the aqueous solution comprises glutamic acid with a mass concentration of 0.2% and calcium chloride with a concentration of 10 mmol / L;

[0086] (3) The soaked rice is placed in an incubator for germination treatment, with a germination time of 24 h, a temperature of 30°C, and a humidity of 80%. After the germination treatment, the rice is dried in an oven at 60°C for 2 h to obtain the GABA-enriched functional rice.

[0087] Technical effects:

[0088] The GABA content and the taste value in the polished rice, the brown rice obtained in step (1), the ungerminated GABA rice, and the germinated GABA rice are detected, and the detection method is the same as in Example 1. The detection results are shown in Table 4:

[0089] Table 4

[0090]

[0091] Comparative Example 3

[0092] The difference from Example 1 is that the chemical stress germination of step (3) is not included, and specifically includes the following steps:

[0093] (1) The paddy is stored at 5°C for 12 h, and then the brown rice is prepared by hulling and removing impurities;

[0094] (2) The brown rice is dried to a moisture content of 14% and then subjected to physical damage treatment, with a current of 30 A for the first sand roller rice mill, a current of 20 A for the second sand roller rice mill, a current of 40 A for the third iron roller rice mill, and a current of 45 A for the fourth iron roller rice mill, to obtain the damaged rice;

[0095] (3) The soaked rice is placed in an incubator for germination treatment, with a germination time of 24 h, a temperature of 30°C, and a humidity of 80%. After the germination treatment, the rice is dried in an oven at 60°C for 2 h to obtain the GABA-enriched functional rice.

[0096] Technical effects:

[0097] The GABA content and the taste value in the polished rice, the brown rice obtained in step (1), the ungerminated GABA rice, and the germinated GABA rice are detected, and the detection method is the same as in Example 1. The detection results are shown in Table 5:

[0098] Table 5

[0099]

[0100]

[0101] Comparative Example 4

[0102] The difference from Example 1 is only that the brown rice is directly subjected to germination treatment, specifically comprising the following steps:

[0103] (1) The paddy is stored at 5℃ for 12h, and then dehulled and impurities removed to prepare brown rice;

[0104] (2) The brown rice is dried to a moisture content of 14% and then soaked in an aqueous solution for 4h for chemical stress germination, with a liquid-to-material ratio of 25, wherein the aqueous solution comprises glutamic acid with a mass concentration of 0.2% and calcium chloride with a concentration of 10mmol / L. Subsequently, the brown rice is subjected to germination treatment in an incubator at a temperature of 30℃ and a humidity of 80% for 24h. After the germination treatment, the brown rice is dried in an oven at 60℃ for 2h to obtain GABA-enriched germinated brown rice.

[0105] Technical effects:

[0106] The GABA content and taste value of the polished rice, the brown rice obtained in step (1), the ungerminated GABA rice and the germinated GABA rice are detected, and the detection method is the same as that in Example 1. The detection results are shown in Table 6:

[0107] Table 6

[0108]

[0109] In summary, the present application proposes a method for synergistically inducing efficient enrichment of GABA in rice by using controllable physical damage combined with specific environmental stress. The GABA functional rice has a moderate softness, and the cooking quality and eating quality are better than those of brown rice and similar to those of polished rice. The GABA content is significantly improved, which can improve the acceptance of consumers. The present application brings a new research idea for replacing the traditional polished rice as the main food and a new opportunity for healthy diet.

[0110] The above merely describes the preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any changes or replacements within the technical scope disclosed by the present application can be easily conceived by those skilled in the art, and should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for inducing functional rice to enrich GABA, characterized in that, After the brown rice was germinated by physical damage and chemical stress, it was soaked in water to accelerate the germination, thereby completing the enrichment of GABA in the functional rice.

2. A method for inducing functional rice to enrich GABA according to claim 1, characterized in that, The brown rice is obtained by storing rice at 0-10° C. for 12-48 hours, husking the rice and removing impurities.

3. A method for inducing functional rice to enrich GABA according to claim 1, characterized in that, The physical damage is handled by two sand and two iron rice mills, among which the current of the one sand roller rice mill is 20-65A, the current of the two sand roller rice mills is 20-30A, the current of the three iron roller rice mills is 40-60A, and the current of the four iron roller rice mills is 40-55A.

4. A method for inducing functional rice to enrich GABA according to claim 1, characterized in that, The chemical stress is to soak the rice in an aqueous solution of glutamic acid and calcium chloride to force the rice to germinate.

5. A method for inducing functional rice to enrich GABA according to claim 4, characterized in that, The soaking time is 2-8 hours, and the liquid-to-solid ratio is 10-50.

6. A method for inducing functional rice to enrich GABA according to claim 4, characterized in that, The mass concentration of glutamic acid in the aqueous solution of glutamic acid and calcium chloride is 0.1-0.5%, and the concentration of calcium chloride is 10-15 mmol / L.

7. A method for inducing functional rice to enrich GABA according to claim 1, characterized in that, The time of the water immersion germination treatment is 12-48 hours, the temperature is 0-35° C., and the humidity is 60-90%.

8. A method for inducing functional rice to enrich GABA according to claim 1, characterized in that, The method further comprises a drying step after the water-immersion germination treatment, wherein the drying temperature is 40-100° C. and the drying time is 1-5 hours.

9. the functional rice enriched in GABA prepared by the method for enriching GABA in a kind of inducing functional rice as described in any one of claim 1-8.

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